"Just 100 days. Exactly 100 days."

A man in a suit looked around at the 20 people standing in front of the gray building and spoke.

"All you have to do is live in that building for exactly 100 days. During that period, we'll provide you with basic supplies and a few missions."

The gazes of the 20 people shifted to the building behind him. It was a lone structure built in the middle of a secluded mountain, hardly a place that could be considered ordinary.

"We won’t interfere with anything that happens inside. After 100 days, we’ll reward you …